home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Shareware Overload Trio 2
/
Shareware Overload Trio Volume 2 (Chestnut CD-ROM).ISO
/
dir26
/
cati49.zip
/
CATI49.TXT
Wrap
Text File
|
1994-07-10
|
54KB
|
1,093 lines
Document 0001
DOCN CATI4901
TI ANTI-HIV AGENTS: AZT 100 mg/day?
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX STEADY DETAILS
Even though thousands of patients have used AZT doctors do not yet
know the minimum `effective' dose. Researchers in Hamburg, Germany,
carried out a small study to find out what that dose might be.
Eighteen men and 2 women were monitored by doctors for 12 weeks as
part of this study while they were taking various doses of AZT. Before
entering this study none of the subjects used AZT. Seven subjects had
AIDS, 7 ARC and the remaining subjects were free from symptoms. For
the first four weeks of the study subjects took AZT 100 mg/day. During
weeks 4 through 8 they took 200 mg/day. For the last 4 weeks of the
study subjects took 500 mg/day of AZT.
RESULTS- RED BLOOD CELLS, PLATELETS
There were no significant changes in red blood cell, platelet and
certain white blood cell counts during the study. As well, blood
levels of Beta2-microglobulin and weight did not change while subjects
were in the study. Indirect measures of HIV production (called p24
antigen) suggested that the amount of virus produced fell during the
study. This decrease was statistically significant, that is, not
likely due to chance alone.
RESULTS--CD4+ AND CD8+ CELLS
After the fourth week of the study there was an average increase of
120 CD4+ cells in the blood of subjects. This increase continued
during the next 8 weeks of the study and was statistically
significant. There were no significant changes in the CD8+ cell counts
during the study.
TOXICITY
There were no serious side effects detected by the study physicians.
SUMMARY
In this study, researchers found that 50 mg of AZT taken "twice daily
[had] a statistically significant effect on [CD4+ cell counts] when
given to [subjects who had never used the drug]." AZT had no effect on
CD8+ cell counts. The doctors warned that further studies need to be
done to find out the effect of low doses of AZT on the appearance of
symptoms of HIV infection.
REFERENCES:
1. Stellbrink HJ, Abrecht H, Plettenberg A, et al. Antiviral and
immunologic effects of escalating low doses of Zidovudine in
HIV-positive patients. European Journal of Clinical Microbiology and
Infections Diseases 1993;12:618-621.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0002
DOCN CATI4902
TI ANTI-HIV AGENTS: AZT and ddI: Combinations Verses Alternating
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX BACKGROUND
A number of long-term studies have found that the benefit(s) of AZT
treatment wanes. The loss of the beneficial effect(s) may be due to
the increasing toxicity of the drug over time, the development of
AZT-resistant virus or other factors. If AZT resistance is an issue
then perhaps treatment with other a HIV drugs may be an option.
Doctors in the USA are conducting a number of clinical trials using
anti-HIV drugs to see if they can help protect the immune system from
further damage by HIV. We now report on one of these trials.
STUDY DETAILS
Doctors in Bethesda, Maryland enrolled 41 subjects for this study.
Subjects were supposed to have received only "3 months or less
antiviral therapy" in the past. As well, the subjects had between 10
and 350 CD4+ cells and were also "free of life-threatening
[infections]" at the time they entered the study. Doctors randomly
assigned subjects into two groups or `arms'. In one arm of the study
subjects received 150 mg of AZT taken every 8 hours and 250 mg of ddI
taken once daily. Subjects took ddI "in the mornings between the two
doses of [AZT]." In the other study arm subjects took "100 mg of AZT
every four hours for 3 weeks."
At the end of the 3 weeks doctors switched the subjects from AZT to
"250 mg ddI every 12 hours for [another] 3 weeks." At the end of this
period they then switched back to AZT taking it in the same dose and
schedule as before. These subjects continued, every 3 weeks, to switch
back and fort between the two regimens for the rest of the study. The
doctors assigned 20 subjects to the alternating arm and 21 to the
combination arm. The trial was not blinded; subjects and doctors knew
which drugs subjects received.
DROP-OUTS AND DEATHS
At the time of data analysis doctors had monitored some subjects for
up to 104 weeks. Two subjects in the "alternating arm died of
[AIDS-related complications]." One subject in the combination arm died
because of complications from an inflamed pancreas. The doctors
suggested that ddI's toxicity to the pancreas may have been the cause
of his death. Two other subjects in the alternating arm of the study
withdrew from the trial.
RESULTS CD4+ CELL COUNTS
Subjects given both drugs at once (the combination arm) had greater
increases in their CD4+ cell counts than subjects in te alternating
arm. As well, the increase in CD4+ cells lasted for up to 45 weeks.
These increases in CD4+ cells in subjects in the combination arm were
statistically significant; that is, not likely due to chance alone.
Although some subjects in the combination arm had increasing CD4+ cell
counts (reaching as high as 108 more CD4+ cells), after the 9th week
of the study these started to decline. Subjects in the alternating arm
had a maximum increase of 40 CD4+ cells 3 weeks after entering the
study.
RESULTS--IMMUNE SYSTEM TESTS
During the study some subjects had an improvement in tests of immune
system function (called delayed type hypersensitivity). But a year
later only 1 subject who improved during the study "preserved [this
improvement]".
VIRUS PRODUCTION
One indirect but cheap and quick way to find out if HIV production is
changing is to measure an HIV protein called p24 antigen, or simply
`p24'. Overall it appeared that subjects on the combination arm had
reduced viral production compared to subjects in the alternating arm.
Only in the 27th week of the study were there any statistically
significant differences between the arms of the study.
WEIGHT
Subjects in both arms of the study gained weight. The largest average
increase happened in the 27th week. In the combination arm that
average increase was 6 kg and in the alternating arm it was 2 kg. This
difference was statistically significant. After te 27th week the
average weight of subjects began to decline in both arms of the study.
LIFE-THREATENING INFECTIONS
At the time of data analysis 3 subjects in the combination arm had 4
life-threatening infections and 6 subjects in the alternating arm had
10 life-threatening infections. This difference was not statistically
significant.
TOXICITY
The researchers think that at least 1 subject died because of the
toxicity of AZT and ddI. Some subjects also had bone marrow and liver
damage which may have been caused by AZT, ddI or both drugs.
SUMMARY
In this study, a combination of AZT and ddI seemed to be tolerated and
caused an increase in weight and CD4+ cell counts compared to a
regimen of alternating AZT and ddI. Whether the increased weight and
CD4+ cell counts resulted in improved quality of life, survival and/or
delayed the decline of the immune system is not at all clear. Larger,
controlled studies may be able to answer these questions.
REFERENCES:
1. Yarchoan R. Lietzau JA, Nguyen B-Y. et at. A randomized pilot
study of alternating or simultaneous Zidovudine and Didanosine therapy
in patients with symptomatic Human Immunodeficiency Virus infection.
Journal of Infectious Diseases 1994;169:9-17.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0003
DOCN CATI4903
TI ANTI-HIV AGENTS: AZT--How Many Times A Day?
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX BACKGROUND
Although some doctors have gained experience using AZT they are not
sure which schedule is best; that is, how many times a day patients
should take the drug. We now present some research that might affect
decisions about AZT schedules.
AZT INSIDE THE CELL
By itself, in its ordinary form, AZT is not an antiviral. When
swallowed, a capsule of AZT eventually breaks open and the drug is
absorbed into the blood. From the blood AZT has to enter T-cells. Once
inside a cell AZT then has to be converted into its "active" or
antiviral form (called AZT triphosphate). To study this processing of
AZT, researchers in the USA have been conducting sophisticated
analyses of blood cells from 12 people with HIV infection who used
AZT.
STUDY DETAILS
The subjects were male and free from symptoms. The doctors gave the
subjects 100 ma of AZT to take orally. Technicians then took blood
samples from the subjects over the next 6 hours.
RESULTS
* the researchers found a wide range of AZT levels in the blood cells
of subjects taking the same oral dose.
* the level of activated AZT (AZT-triphosphate) increased in all
subjects during the first and second hour after swallowing a dose of
the drug. After the second hour the concentration of processed AZT
remained the same for at least the next 4 hours. The amount of AZT
processed during this time varied from one subject to another.
However, the doctors found the general pattern of increasing
concentrations of activated AZT during the first 2 hours, and a
stable concentration after that time, in all subjects. These results
raise questions about current schedules for taking AZT.
In this study it seems that taking the drug every 6 hours might be
one possible schedule. Further experiments need to be done to
Confirm and explore the issue of AZT schedules.
REFERENCES:
1. Robbins BL, Rodman J. McDonald C et al. Enzymatic assay for
the measurement of Zidovudine triphosphate in peripheral blood
mononuclear cells. Antimicrobial Agents and Chemotherapy 1994;38(1):
1 15-121
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0004
DOCN CATI4904
TI IMMUNOMODULATORS: AZT, Pentoxifylline and TNF
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX BACKGROUND
The body produces a number of chemical messengers that help the immune
system coordinate, focus and withstand attacks by invading
microorganisms as well as tumours. One of these chemicals is TNF
(tumour necrosis factor). Researchers do not fully understand the
effects of TNF and much work on it continues. We now present results
from a short trial in the USA.
STUDY DETAILS
Researchers reported results on 32 HIV-infected subjects (28 men and
4 women). The average CD4+ cell count of subjects was about 300 cells
and the average CD8+ cell count was almost 900 cells. Subjects were
divided into 3 groups; group 1 received 400 to 500 mg/day of AZT;
group 2 received pentoxifylline 400 mg three times daily; and group 3
received a combination of regimens 1 and 2. The researchers monitored
all groups for 3 months.
RESULTS
No life-threatening inactions appeared during the study. Blood levels
of TNF and Beta2-microglobulin did not change significantly among the
3 groups. The average CD4+ and CD8+ cell counts did not change
significantly among the 3 groups over the course of the study. The
amount of virus produced in subjects given the combination of AZT and
pentoxifylline was 4 times less than in subjects in the other 2
groups. This difference in viral production was statistically
significant; that is, not likely due to chance alone. Pentoxifylline
did not cause any bone marrow damage and was "well tolerated". It is
interesting that the researchers used P24 antigen (an indirect way of
measuring viral production). They found that results from P24 antigen
tests were not reliable. The researchers suggested longer and larger
studies of this combination of drugs may be needed to see if reducing
HIV production can have an effect on quality of life and survival.
OTHER STUDIES
Researchers in Milan, Italy, have been studying nearly 200 subjects at
various stages of HIV infection. They could not find a link between
blood levels of TNF and decreasing CD4+ cell counts. In 25 subjects
with high blood levels of TNF 500 mg of AZT every "48 hours" for 3
months caused TNF levels to fall. This change was statistically
significant and had no effect on CD4+ cell counts.
REFERENCES:
1. Luke DR, McCreedy BJ, Sarnoski TP, et al. Phase I/II study of
pentoxifylline with Zidovudine on HIV-1 growth in AIDS patients.
International Journal of Clinical Pharmacology, Therapy and Toxicology
1993;31(7):343-350.
2. Cremoni L, Vaira LL. Grassi MG and Millazzo F. Does Zidovudine
reduce tumour necrosis factor-alpha in HIV-positive patients? AIDS
1993;7(1):128-129.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0005
DOCN CATI4905
TI IMMUNOMODULATORS: Pentoxifylline, TNF and the Immune System--A
Delicate Balance
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX BACKGROUND
The body produces a number of chemical messengers that help the immune
system coordinate, focus and withstand attacks by invading
microorganisms as well as tumours. One of these chemicals is TNF
(tumour necrosis factor). Researchers have limited information on the
effects of TNF and much work on it continues.
TNF INJECTIONS
In the late 1980s one group of researchers in the USA tested the
effect of injections of TNF (tumour necrosis factor) on the health of
subjects with HIV infection. During the 4-month double-blind study
some subjects received 10 ug per square mete of skin 3 times per week.
When the researchers analysed the data they found that there was no
short-term benefit or risk from the injections of TNF. Now other
researchers are taking a different approach and are using the drug
Trental(R)(pentoxifylline) to try and reduce blood levels of TNF in
subjects with HIV/AIDS.
DECREASING TNF
In some laboratory experiments with HIV-infected cells, TNF seems to
increase production of HIV by those cells. TNF may also cause weight
loss in HIV-infected patients. Thus it seems reasonable to think that
by reducing production of TNF some HIV-infected patients may regain or
maintain their weight and/or reduce production of HIV.
PENTOXIFYLLINE RISKS
TNF plays a very important role as part of the immune system's
defenses against tumours and infections. By severely reducing
production of TNF pentoxifylline may make some patients more
vulnerable to some infections. As well, some researchers have found
that the interaction between pentoxifylline and the immune system is
more complex and pentoxifylline may suppress more than just TNF. This
could cause some HIV-infected patients to become at higher risk for
certain infections. In patients whose immune systems are already
damaged by HIV infection, adding yet another immunosuppressive drug
may be risky.
REFERENCES:
1. Agosti JM, Coombs REV, Collier AC, et al. A randomized,
double-blind, phase I/II trial of tumour necrosis factor and
interferon gamma for the treatment of AIDS-related complex (protocol
025 from the AIDS Clinical Trials Group). AIDS Research and Human
Retroviruses 1992;8(5):581
2. Hilsh CS, Ellner JJ, Russell DG and Rich EA. Complement
receptor-mediated uptake and tumour necrosis factor-alpha-mediated
growth inhibition of Mycobacterium tuberculosis by human alveolar
macrophages. Journal of Immunology 1994;152:743.
3. Jewett A and Bonavida B . Pentoxifylline suppresses
interleukin-2-mediated activation of immature human natural killer
cells by inhibiting endogenous tumour necrosis factor-alpha secretion.
Journal of Clinical Immunology 1994;14(1):31-38.
4. Thanhauser A, Roiling N. Bonhle A. Pentoxifylline: a potent
inhibitor of IL-2 and INF-gamma biosynthesis and BCG-induced
cytotoxicity. Immunology 1993;80:151-156.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0006
DOCN CATI4906
TI IMMUNOMODULATORS: Steroids
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX BACKGROUND
"Steroids" (corticosteroids) are drugs that suppress and reduce many
of the activities of the immune system. Doctors sometimes find them
useful in treating certain conditions such as arthritis and psoriasis.
During some of the life-threatening infections seen in AIDS such as
PCP, 'toxo' (toxoplasmosis) and 'crypto' (cryptococcal meningitis) the
resulting inflammation and swelling can be dangerous. This is why
doctors sometimes prescribe steroids to reduce the inflammation until
the infection can be brought under control. As steroids can affect the
immune system, bone marrow and brain, side effects can be expected.
Last year doctors in England found that patients who had less than 50
CD4+ cells appeared to be at increased risk for developing te
sight-threatening infection CMV retinitis as a result of using
steroids.
REFERENCES:
1. Chrousos GP, Wilder RL, Cupps TR and Balow JE. Glucocorticoid
therapy for immune-mediated diseases: basic and clinical correlates.
Annals of Internal Medicine 1993:119(12):1198-1208.
2. Nelson MR, Erskine D, Hawkins DA and Gazzard BC. Treatment
with corticosteroids a risk factor for the development of clinical
cytomegalovirus disease in AIDS. AIDS 1993;7:375-378.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0007
DOCN CATI4907
TI IMMUNOMODULATORS: Steroids for MAC
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX BACKGROUND
Infection with MAC/MAI (Mycobacterium avium complex/Mycobacterium
avium intracellulare, the two are interchangeable) can happen as the
CD4+ cell count falls below 100 cells. The symptoms of MAC are not
pleasant and may include fever, night sweats, persistently swollen
lymph nodes, diarrhea weight loss and fatigue. MAC infection may also
affect the bone marrow and cause reduced production of red blood cells
resulting in anemia. Only in the 1990s did two powerful antibiotics
such as azithromycin and clarithromycin become licensed in North
America and the EU. Even so MAC can rapidly become resistant to the
effects of either of these drugs when used alone. A number of trials
are underway to test various combinations of antibiotics against MAC
infection.
ANTIBIOTICS
Doctors in England have recently reported their experience with
steroids to treat 2 patients with MAC infection. Both patients were
male and had less than 40 CD4+ cells. Their symptoms included "fever,
night sweats and weight loss." one patient "developed anemia". At
first doctors gave these patients the antibiotics rifampin, isoniazid
and pyrazinamide. These antibiotics were not effective. So the doctors
then prescribed azithromycin 1 gram/day and clofazimine 100 mg/day for
1 patient while the other got Cipro(R)(ciprofloxacin) 1 gram/day,
azithromycin 1 gram/day and clofazimine 100 mg/day. Lab tests on stool
and blood samples, taken at the time they first developed symptoms
detected MAC.
RESULTS
Within 2 weeks of starting the second antibiotic regimen both patients
had diminished] fever and sweats." Despite this the anemic patient had
to receive blood transfusions..
STEROIDS
The doctors then prescribed 20 mg/day of the steroid Prednisone after
which the fever and night sweats cleared (this steroid is different
from the kind used by some athletes to increase muscle size). They
also enjoyed "a feeling of well-being." The patients gained weight
and, while continuing to take azithromycin and clofazimine or Cipro,
have not developed sweats and fever. Five months later one patient has
maintained his weight but developed a fungal infection in his mouth
that was resistant to antifungal drugs. The doctors have reduced his
dose of steroids to 10 mg/ day hoping to restore some immunity against
the fungus. At 8 months after beginning his anti-MAC therapy the
second patient is well enough to return to work (the doctors did not
provide details about his job).
HOW HAVE STEROIDS HELPED/HARMED?
Steroids can block the production of chemicals called cytokines which
are used by cells of the immune system to send-messages to each other.
Cytokines affected by Prednisone include TNF (tumour necrosis factor)
and interferon-gamma, among others. Suppressing production of
excessive amounts of TNF may reduce fever and weight loss and
production of HIV. Some researchers are concerned that steroids may
speed up the decline of the immune system in people with HIV
infection. Indeed, some studies have found tat steroids can increase
the appearance of Kaposi's sarcoma, CMV retinitis and other herpes
virus infections and perhaps fungal infections as well. Data from
these two patients suggest that in the short term steroids may be
useful and carry some risk. The appearance of drug-resistant fungus in
one patient does raise concerns about the risks of steroid therapy. As
well, there may be the overall impact on their survival in the long
term. In a future issue of TreatmentUpdate we will report results from
other studies where HIV-infected patients were also treated with
steroids.
REFERENCES:
1. Steven N. Pithie Ask Wood M and Innes J. Corticosteroid
therapy for AIDS patients with Mycobacterium avium-intracellulare
infection. AIDS 1994;8(1):136-138.
2. Shiratsuchi H. Johnson JL, Toosiz and Ellner JJ. Modulation of
the effector function of human monocytes for Mycobacterium avium by
Human Immunodeficiency Virus-1 envelope protein gp120. Journal of
Clinical Investigation 1994;93:885.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0008
DOCN CATI4908
TI INFECTION FIGHTERS: Living longer but...
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX BACKGROUND
Compared to the early part of the 1980s some people with HIV/AIDS are
living longer. One possible explanation is that doctors have gained
more experience in treating many of the life-threatening infections
that affect people with HIV/AIDS. New and better antimicrobial agents
(antibiotics/antifungals/ antivirals) or combinations of these drugs
may also have played a role. Unfortunately, most of the anti-HIV
agents in use or being tested do not result in improved survival in
the long term compared to placebo. This is because these drugs cannot
help the immune system to repair the damage caused by years of HIV
infection. Thus, although some patients are living longer thanks to
antimicrobial drugs, their immune systems continue to degrade. One
microorganism that causes serious problems for some patients with AIDS
is MAC/MAI (Mycobacterium avium complex/Mycobacterium avium
intracellulare; they cause the same symptoms, respond to the same
drugs so for this article they can be considered the same).
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0009
DOCN CATI4909
TI INFECTION FIGHTERS: Signs/Symptoms of MAC infection
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX WHERE TO FIND MAC
MAC/MAI are related to the bacteria that cause leprosy and
tuberculosis. MAC is found in tap, river and sea water, soil, dairy
products and animals, including insects. In North America the number
of people becoming ill from serious MAC infection is increasing at the
rate of about 20% per year. Signs/symptoms include:
* night sweats
* fevers
* unintentional weight loss
* diarrhea
* unusually low levels of white and red blood cells
* high blood levels of the liver enzyme alkaline phosphatase
* painful intestines
ANTIBIOTICS
Some doctors in the USA think that MAC infection may eventually affect
"most if not all" people with HIV infection. When MAC spreads to
several sites in the body (bone marrow, blood, spleens liver and
intestines) quality of life and survival decrease. Until the 1990s
common antibiotic regimens were not effective and were toxic as well.
The testing of new antibiotics such as azithromycin and clarithromycin
and rifabutin has made treating and suppressing MAC infection much
easier in the short term.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0010
DOCN CATI4910
TI INFECTION FIGHTERS: Rifabutin--results from placebo-controlled studies
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX BACKGROUND
Researchers in Canada and the USA have conducted two clinical trials
(called 023 and 027) to test the ability of rifabutin to delay the
appearance of MAC infection. That drug was released in the 1980s on a
compassionate basis for people with MAC infection, see TreatmentUpdate
30 for details. Data collected from the 1980s suggested that 300
mg/day of rifabutin was more effective than 150 mg/day. For the
purposes of this report data from the two studies (023 and 027) will
be combined.
TRIAL DETAILS
All subjects enrolled had less than 201 CD4+ cells and had AIDS. Over
95% were male and over 1100 were randomly assigned to one of two arms
or groups; either rifabutin 300 mg/day (566 subjects) or a dummy
capsule or placebo (580 subjects). On average all subjects had high
blood levels of the liver enzyme alkaline phosphatase. At the
beginning of the study 10 subjects had MAC detected in their blood
samples and they were not used in the data analysis. Subjects were not
supposed to be using anti-MAC/TB drugs. Subjects continued to stay in
the study until certain events or end points occurred. When one event
or endpoint occurred the researchers unblinded the data on that
subject to find out if he/she was on placebo or rifabutin. At that
point subjects were allowed to receive rifabutin if they chose. End
points in the trial included:
* detectable MAC from bone marrow or blood samples
* detectable TB from blood/bone or other samples
* subjects became ill and had to receive anti-TB/ MAC therapy
* "serious or life-threatening toxicity caused by study drugs or [some
other] cause"
RESULTS--MAC INFECTION
On averages during the double-blind phase of the trial, the following
became infected with MAC:
* 17% of subjects given placebo
* 8% given rifabutin
These differences between placebo and rifabutin were statistically
significant; that is, not likely due to chance alone. From this data
it is clear that rifabutin can delay the appearance of MAC in some
subjects.
RESULTS--CD4+ CELL COUNTS
At least half of the subjects had a CD4+ cell count between 12 and 15
cells when technicians detected MAC in blood/bone/tissue samples. The
researchers did not provide data on CD8+ cell counts.
RESULTS--TB
Doctors diagnosed 7 of the 1146 subjects with having TB. Technicians
could not find any TB-causing bacteria in blood/bone/tissue samples
from these subjects.
RESULTS--SIGNS/SYMPTOMS
Rifabutin, compared to placebo reduced:
* fever
* fatigue
* high blood levels of the liver enzyme alkaline phosphatase
* anemia
* the need for hospitalization
This reduction in signs/symptoms between the subjects on rifabutin and
others on placebo was statistically significant. Rifabutin did not
affect:
* weight loss
* night sweats
* diarrhea
* intestinal pain
RESULTS--SURVIVAL
Roughly similar proportions of subjects died in each arm of the study;
200 on rifabutin and 226 on placebo. This difference between the two
arms of the study was not statistically significant.
TOXICITY
A small proportion of subjects (16% on rifabutin and 8% on placebo)
had to leave the study because of side effects. These adverse
reactions included:
* rash
* gastrointestinal problems
* low levels of a type of white blood cell called neutrophils.
That these side effects were not reduced by rifabutin is not
surprising as the drug can cause these effects.
REFERENCES:
1. Nightingale SD, Cameron DW, Gordin FM. Two controlled trials
of rifabutin prophylaxis against Mycobacterium avium complex infection
in AIDS. New England Journal of Medicine 1993;329(12):828-833.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0011
DOCN CATI4911
TI INFECTION FIGHTERS: Who benefits from rifabutin?
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX SUMMARY
Data from trials 023 and 027 suggest that rifabutin 300 mg/day can:
* reduce blood levels of MAC
* reduce the intensity of some symptoms: fatigue and fever
* reduce the need to put patients in hospital because of symptoms of
MAC infection
* reduce the incidence of red blood cell anemia
DRUG RESISTANCE
Technicians could not detect any rifabutin-resistant bacteria from
subjects during the study.
RISKS
* no increase in survival in subjects given rifabutin compared to
others given placebo during the double-blind phase of the study
* some toxicity to the bone marrow and possibly the immune system
* rash
RIFABUTIN--WHO BENEFITS?
In this study, during the double-blind period, roughly 8% of subjects
on rifabutin and 17% on placebo developed MAC infection. This means
that only 9% clearly had benefit and another 8% worsened despite being
given rifabutin. For 83% of subjects there was no benefit to being
given rifabutin. Based on the data provided by the manufacturer, Adria
Laboratories, 100 people had to be given rifabutin for 9 to show
benefit from the drug. These figures are not surprising; rifabutin is
clearly a weak antibiotic and there was no statistically significant
difference between the two groups when statisticians looked at
survival.
RIFABUTIN AND FLUCONAZOLE--WHICH DOSE?
One prominent Canadian researcher told us privately that there may be
other factors that need to be considered--the toxicity and the dose of
rifabutin. At the International AIDS Conference in Berlin last year
doctors presented an abstract on an interaction between rifabutin and
fluconazole. They found that in 12 patients taking fluconazole 200
mg/day and 300 mg/day of rifabutin that blood levels of rifabutin
increased between 2 and 3 times their normal levels. Some researchers
think that taking 450 mg/day of rifabutin will make the antibiotic
more effective. Others are not so sure, because at higher doses
rifabutin becomes more toxic to patients with AIDS. As well, there are
increasing reports of eye inflammation in patients using rifabutin. In
one report, this condition resolves once the patient stops using
rifabutin.
WEIGHING RISK/BENEFIT
These results do not mean that rifabutin should not be considered as
preventative therapy against MAC. The real issue is how to get the
greatest benefit from the drug. According to the company, subjects who
may benefit the most from rifabutin are probably those with CD4+
counts of 75 cells or less. Some doctors who were not affiliated with
Adria Laboratories or this study suggest that frequent monitoring of
patients (including sending stool and blood samples for laboratory
detection of MAC) and paying close attention to symptoms are
important. They "save" rifabutin until it is clear that the patient's
immune system cannot cope (symptoms become worse and lab tests detect
MAC) with MAC infection and prescribe rifabutin in combination with a
number of antibiotics. We have also heard anecdotal reports from
doctors that some of their patients may develop symptoms of MAC which
get confirmed by laboratory testing. By the time the test result
returns to the doctor the patient has recovered, often without
treatment. These courses of action are not recommended by the United
States Public Health Service.
REFERENCES:
1. Frank MO, Graham MB, Wispelway B. Rifabutin and uveitis. New
England Journal of Medicine 1994;330(19):868.
2. Trapnel CB, Narang PK, Li R. et al. Fluconazole increases
rifabutin absorption in HIV-positive patients on stable Zidovudine
therapy. IX International Conference on AIDS Berlin 1993, abstract
PO-B-31-2212, page 504.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0012
DOCN CATI4912
TI INFECTION FIGHTERS: Detecting and preventing MAC infection
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX WIDESPREAD (DISSEMINATED) INFECTION
When technicians find a sample of blood containing MAC then the
infection is no longer contained and doctors describe it as
"disseminated". Some doctors also make the same diagnosis based on a
sample of bone marrow or liver cells that test 'positive' for MAC.
STANDARD PROCEDURES TO FIND MAC
To detect MAC a small amount of blood (10 ml) is collected by a nurse
or lab technician in a tube. They then put a small amount of an
anti-clotting drug into the tube. This does not reduce the number of
bacteria even if the blood is kept up to a week after being collected.
Technicians later spread the blood on containers with nutrients that
MAC needs in order to survive. In Bactec devices MAC can be grown in
1 to 2 weeks. In other systems it can take 2 to 3 weeks, sometimes
even longer. In a future issue of TreatmentUpdate we will provide more
details on using PCR (polymerase chain reaction) for detecting MAC.
MAC PREVENTION RECOMMENDATIONS
According to the US Public Health Service, patients with less tan 100
CD4+ cells should get preventative therapy for the rest of their
lives. These patients should not have active TB or MAC infection. To
confirm this, x-rays blood cultures and TB skin tests may be
necessary. Preventative therapy against MAC should be 300 mg/day of
rifabutin.
DIFFICULT DECISIONS
The US Public Health Service recommended that in reaching a decision
about preventative MAC therapy, doctors should weigh the following
carefully:
* rifabutin toxicity
* rifabutin's interaction with other drugs
* the cost of rifabutin
* the willingness of patients to take the drug as directed
* drug resistance
TREATMENT
The US Public Health Service recommended the following when treating
patients with MAC:
* a minimum of 2 antibiotics should be prescribed
* all regimens should include azithromycin or clarithromycin
* ethambutol is probably a useful second drug
For third or fourth drugs, they suggested the following options:
* Cipro(R), rifabutin, rifampin and clofazimine
* isoniazid and pyrazinamide should not be used
* in cases where patients are using rifabutin as a preventative and
they develop disseminated MAC infection, rifabutin can still be used
as part of a treatment regimen.
The task force stated that patients who "responder to therapy will
improve during the "first 4 to 6 weeks of therapy." If patients do not
improve after the "first 4 to 8 weeks of therapy they should be
reevaluated."
REFERENCES:
1. Nightingale SD, Cameron DW, Gordin FM. Two controlled trials
of rifabutin prophylaxis against Mycobacterium avium complex infection
in AIDS. New England Journal of Medicine 1993;329(12):828-833.
2. Masur H. Public Health Service Task Force on Prophylaxis and
Therapy for disseminated Mycobacterium avium complex disease in
patients infected with human immunodeficiency virus. New England
Journal of Medicine 1993;329:898-904.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0013
DOCN CATI4913
TI INFECTION FIGHTERS: Mepron as PCP prevention
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX BACKGROUND
Although there are several effective antibiotics with which to treat
the life-threatening pneumonia PCP, many patients cannot tolerate
them. This intolerance arises because patients become sensitive to
sulfa drugs. This sensitivity is a problem because many of the drugs
used to treat PCP are also taken in smaller doses as PCP prevention or
prophylaxis. Patients may find themselves using aerosolized
pentamidine which is not the best therapy. The new antiparasite drug
Mepron(R)(atovaquone) works as a treatment for mild-to-moderate PCP.
Mepron can be tolerated by many patients who are allergic to sulfa
drugs. Some doctors are considering using Mepron as a prophylaxis for
their patients allergic to sulfa.
RESULTS FROM ENGLAND
Doctors in England have reported their experience using Mepron as
prophylaxis against PCP in 3 patients. All subjects had less than 10
CD4+ cells and had PCP 2 to 5 times. The patients could not tolerate
Bactrim/Septra, dapsone, or aerosolized pentamidine. They received
Mepron 750 mg three times daily. One patient has used it for 3 months,
another 5 and the third 6 months. No patient has developed PCP while
on this regimen. While more research on Mepron needs to be done, this
report does offer some hope to patients allergic to sulfa drugs.
REFERENCES:
1. Fisher MJ, Gazard BG, Hawkins DA and Nelson MR. Atovaquone as
prophylaxis against Pneumocystis carinii pneumonia. Journal of
Infection 1994;103-104.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0014
DOCN CATI4914
TI INFECTION FIGHTERS: Toxo with high CD4+ cell counts
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX The parasite T. gondii can infect the brain causing the
life-threatening infection 'toxo' (toxoplasmosis). People can get
infected with the parasite by eating raw or undercooked meat and also
by accidentally eating cat feces. Most cases of toxo occur in patients
when the CD4+ cell count falls below 200 cells. However, Italian
researchers have found 4 cases of toxo in patients with more tan 600
CD4+ cells. These patients 2 males and 2 females, all adults, had
symptoms such as seizures, worsening headache and sensitivity to
light. As well, tests detected antibodies against the parasite in
their blood. Treated with "50 to 75 mg/day of pyrimethamine and
sulfadiazine 100 mg/kilogram of body weight/day" they recovered over
the course of 6 weeks. No lesions appeared when doctors examined the
X-ray scans of their brains. These patients are now on suppressive
therapy: 25 mg/day of pyrimethamine and 2 grams/day of sulfadiazine,
and remain healthy. Their CD4+ cell counts are still above 600 cells.
The doctors suggest that HIV-infected patients who have relatively
high CD4+ cell counts and who develop neurological problems should be
investigated for toxo.
REFERENCES:
1. Gervasoni C, Bini T. Franzetti F. et al. Central nervous
system toxoplasmosis in HIV-1-infected patients with persistently
normal CD4+ cell counts. European Journal of Infectious diseases
1993;12(10):787.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0015
DOCN CATI4915
TI TOXICITY: AZT toxicity may be linked to biorhythm
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX BACKGROUND
As plants and animals have a 24-hour cycle some researchers think that
cycle might influence the effect of drugs inside the body. Researchers
at the Comprehensive Cancer Center, Birmingham, Alabama, have been
performing experiments on rats to find out if the toxicity of AZT may
be linked to daily biorhythms.
STUDY DETAILS
In the first part of the experiments technicians placed the rats in
cages (with food and water) and turned the lights off and on to
produce the effect of night and day. The technicians maintained these
conditions for 4 weeks to let the rats adjust. After this, in the
second phase of the experiment, technicians gave most of the rats
various doses of AZT at different times of day/night. The rats that
did not get AZT were kept as a "control" for comparison.
RESULT--NIGHT AND DAY
All rats given AZT suffered from weight loss. The mice that
experienced the greatest weight loss received AZT at 4 a.m. This
finding was statistically significant; that is, not likely due to
chance alone. Rats given AZT had bone marrow damage and reduced
production of red and white blood cells. The rats suffered the least
toxicity when they received AZT at 2 pm or 5 pm. These observations on
toxicity and time of administration of AZT were statistically
significant.
RESULTS--DEATH
Among the rats that died, the cause was usually bone marrow damage
caused by AZT. The death rate was highest (80%) when rats received AZT
at midnight. Only half the rats died when given the same dose of AZT
at noon. These differences in the death-rates were statistically
significant.
SUMMARY
Twenty-four-hour biorhythms can have an impact on how animals are
affected by various drugs. In these experiments on rats with AZT, the
timing of the dose clearly had different effects at different points
in their day/night cycle. These results may not be exactly the same in
humans who also have a 24-hour biorhythm. According to the researchers
rats and mice are "more active in the [night] and less active in the
light". Humans are generally more active in the light and less active
at night. Experiments on human bone marrow cells also suggest that the
cells are most active during the period when people are awake and
least active during sleep; between midnight and 4 am. Further studies
need to be done to find the time when humans are least affected by the
toxicity of AZT and other, related drugs. Researchers in France have
also reported results from a study on subjects with cancer who did not
have HIV infection. The researchers also found that biorhythms
affected the toxicity of interferon-alfa.
REFERENCES:
1. Zhang R. Lu Z. Diasio CR, et al. The time of administration of
3'-azido-3'- deoxythymidine (AZT) determines its host toxicity with
possible relevance to AZT chemotherapy. Antimicrobial Agents and
Chemotherapy 1993;37(9):1771-1776.
2. Depres-Brummer, Levi F. Di Palma M, et al. A phase I trial of
91-day continuous venous infusion of alfa-interferon at circadian
rhythm modulated rate in cancer patients. Journal of Immunotherapy)
1991;10:440-447.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.
Document 0016
DOCN CATI4916
TI TOXICITY: Foscarnet toxicity in women
DT 9405
AU Sean Hosein, Editor
SO Community AIDS Treatment Information Exchange (CATIE) -
TreatmentUpdate No. 49: A Publication of the Community AIDS Treatment
Information Exchange, Suite 324 - 517 College Street, Toronto, Ontario
M6G 4A2 - (416) 944-1916.
TX BACKGROUND
Foscarnet (Foscavir(R) is a drug licensed for the treatment of the
sight-threatening infection CMV retinitis. Foscarnet can also block
the production of other herpes viruses HIV and the hepatitis B virus.
Unlike another anti-CMV drug, DHPG (Cytovene(R), ganciclovir),
foscarnet is not toxic to the bone marrow. Foscarnet can, however,
cause kidney damage. In uncircumcised men treated with foscarnet,
ulcers may develop on the penis. This happens because foscarnet is
released in the urine at relatively high concentrations. Urine
containing foscarnet may collect in the folds of skin where it can
form ulcers. Doctors in England have reported that ulcers can also
form in women who use foscarnet. In one woman, the ulcers appeared on
the labia and healed once she stopped taking the drug. Just as
cleaning the foreskin after urination may help reduce the appearance
of ulcers in men, cleaning the external genitals after urination may
also help women who use foscarnet.
REFERENCES:
1. Lacey HB, Ness A, Mandal BK. Vulval ulceration associated with
foscarnet. Genitourinary Medicine 1992;68: 182.
DISTRIBUTED BY GENA/aegis (714.248.2836). Copyright (c) 1994.
Community AIDS Treatment Information Exchange (CATIE). Noncommercial
reproduction encouraged.